No 199 September 2017

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Exploring new therapies

ANDREW ATKINS
 

Andrew Atkins is Nurse Consultant, South Australia Adult Haemophilia Treatment Centre

Nurses at ISTH 2017
Australian nurses at ISTH. L-R: Robyn Shoemark, Andrew Atkins, Megan Walsh, Helen Starosta, Alex Connolly

At ISTH 2017 there was a large interest in the latest developments in haemophilia care. The program was well structured with the opportunity to hear presentations on similar topics over different days.

PERSONALISED TREATMENT REGIMES

Speakers in one of the opening sessions discussed the trough levels (ie, the lowest concentration level of the drug before the next dose is administered) now considered achievable for patients on extended half-life (EHL) products for factor VIII (8) and factor IX (9) and the associated cost. EHL products are now in use in some countries, and so the ability is now there to treat people with haemophilia according to their individual half-lives, bleeding patterns and lifestyle, rather than simply reaching a 1% trough level before administering a next dose. In Australia there are now at least two new mathematically-based programs to calculate one’s factor VIII or IX half-life. These programs require less blood tests, making them more convenient, and also provide the ability for a more personalised and more achievable treatment regime.

A debate followed over the use of extended half-life factor IX versus gene therapy. Which is better? Laser eye surgery was used as an example. It was pointed out that while laser treatment is available to correct vision, most people choose to opt for wearing glasses because they are an adequate ‘fix’ with known side effects…this was countered that gene therapy is seeing promising results and without investigation we will never move forward to better treatment.

EMERGING THERAPIES

A number of talks centred on the new therapies, and outlined what they were and their mode of actions. Other than extended half-life factors, emerging concepts/agents for haemophilia include:

Products that mimic clotting factors – emicizumab (ACE910) is an antibody manipulated to bridge activated factor IX (9a) and factor X (10) and therefore replace the action of factor VIII. It has a half-life of 4-5 weeks and is being trialled as a subcutaneous injection, either weekly, fortnightly or monthly, for the treatment of haemophilia A with and without inhibitors. The Haven-1 study results for people with haemophilia A with inhibitors (109 participants) were outlined showing a reduction in annual bleed rates of 87%. There were zero bleeds in over 60% of patients who were randomised to a prophylaxis regime. Serious thrombotic events were seen in 5 patients with inhibitors when bleeding events were treated with their previous by-passing agent treatment regime.  This has resulted in strict treatment guidelines for the use of bypassing agents in conjunction with emicizumab. The Haven-2 (paediatric study) initial findings were also presented showing promising results. Haven-3 and 4 studies are currently underway to study emicizumab in people with haemophilia A without inhibitors and the results of these trials are eagerly awaited in the haemophilia community worldwide. Three other studies involving different drugs/mechanisms are also being developed for trials.

Products that suppress the body’s natural clot regulators to offset the effect of haemophilia – studies looking at the effects of reducing either anti-thrombin or anti-TFPI (tissue factor pathway inhibitor) are being planned. These products intend to protect against bleeding using a completely different method than simply replacing the missing factor. Reducing the naturally occurring thrombin inhibitor will increase thrombin generation and therefore offset the propensity to bleeding in haemophilia. TFPI’s natural effect is to self-limit one of the pathways of clotting, so reducing its levels is also aimed to protect against bleeding. Trials with these products as subcutaneous injections are aimed with haemophilia A or B.

Gene therapy to restore factor production via a single intravenous injection - after following results for over 6 years in one haemophilia B study, mean factor IX levels rose to 5%, and in a more recent study to over 15% after one year. Both studies have seen a 90% reduction in annual bleed rates and factor IX use. For haemophilia A, initial results in one study outlined saw factor VIII peak levels ranging from 12% to 271%, with levels remaining increased after 44 weeks. An immune response side effect was seen in 25% of study participants, but in all cases were treatable with steroid.

NURSE FORUM

Alongside the opening days of the Congress were two Nurse Forum days. This is the first time two days have been allocated. It provided a great opportunity to hear practical advice about nursing practice in Germany, approaches to research, and nurse-led research. While much of the presentations concentrated on clotting disorders there were a number of thought-provoking talks on managing bleeding disorders. One particularly enjoyable theme centred on challenges facing both patients and nurses in religiously diverse communities (Amish, Muslim and Jewish) – ways of managing these select groups gave insight into thinking outside the square when providing care in extraordinary circumstances.

Five nurses from around Australia were fortunate to be able to attend the Congress. It was well worth attending and hopefully more nurses will be able to attend the 2019 Congress in Melbourne.

 

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Date last reviewed: 21 September 2017